public override TerrainGrid Generate(Vector size, FreqDict freqs = null, Random rand = null)
{
freqs = freqs ?? _defaultFreqs;
UpdateFreqs(ref freqs);
NormalizeFreqs(ref freqs);
rand = rand ?? new Random();
var terrain = new Grid<TerrainType>(size);
var heightGrid = _topographyGenerator.Generate(terrain.Size, rand);
heightGrid = _filters.OpenClose(heightGrid);
var sortedPoints = heightGrid.GetPoints().ToList();
sortedPoints.Sort((lhs, rhs) => (heightGrid[lhs] - heightGrid[rhs]));
int numTiles = size.x * size.y;
int numWaterTiles = (int)(numTiles * freqs[TerrainTypes.Water]);
var waterTiles = sortedPoints.Take(numWaterTiles);
foreach (var point in waterTiles)
terrain[point] = TerrainTypes.Water;
int numMountainTiles = (int)(numTiles * freqs[TerrainTypes.Mountain]);
var mountainTiles = sortedPoints.Skip(numTiles - numMountainTiles);
foreach (var point in mountainTiles)
terrain[point] = TerrainTypes.Mountain;
var landTiles = new HashSet<Vector>(terrain.GetPoints());
landTiles.ExceptWith(waterTiles);
landTiles.ExceptWith(mountainTiles);
AddLandTiles(ref terrain, landTiles.ToList(), freqs, rand);
return terrain;
}
private void UpdateFreqs(ref FreqDict freqs)
{
var terrainValues = ((TerrainType[])Enum.GetValues(typeof(TerrainType)));
foreach (var terrainValue in terrainValues)
if (!freqs.ContainsKey(terrainValue))
freqs[terrainValue] = _defaultFreqs[terrainValue];
}
private void NormalizeFreqs(ref FreqDict freqs)
{
double sum = freqs.Values.Sum();
var terrainValues = ((TerrainType[])Enum.GetValues(typeof(TerrainType)));
foreach (var key in terrainValues)
freqs[key] = freqs[key] / sum;
}
private void AddLandTiles(ref TerrainGrid terrain, List<Vector> landTiles, FreqDict freqs, Random rand)
{
var heightGrid = _topographyGenerator.Generate(terrain.Size, rand);
heightGrid = _filters.OpenClose(heightGrid);
landTiles.Sort((lhs, rhs) => (heightGrid[lhs] - heightGrid[rhs]));
int numTiles = terrain.Size.x * terrain.Size.y;
foreach (var terrainType in TerrainTypes.Land)
{
int numTerrainTiles = (int)(freqs[terrainType] * numTiles);
var tiles = landTiles.Take(numTerrainTiles);
foreach(var point in tiles)
terrain[point] = terrainType;
landTiles.RemoveRange(0, numTerrainTiles);
}
}
